This invention relates generally to digital frequency synthesizers and more particularly to digital frequency synthesizers adapted to produce radio frequency signals.
As is known in the art, one type of digital frequency synthesizer includes a plurality of highly stable oscillators coupled to a plurality of counters or frequency multipliers to produce subharmonic frequency signals. These signals are then selectively combined using heterodyning mixers and filters to produce a signal having the desired frequency. Such apparatus is relatively expensive and not generally suited to produce signals having relatively short time durations such as pulses used in radar and pulse communication systems.